AK5371A Datasheet, PDF (13/32 Pages) Asahi Kasei Microsystems – 2ch A/D Converter with USB I/F

ASAHI KASEI
[AK5371A]
„ EEPROM I/F
The AK5371A has EEPROM I/F for customizing Device Descriptor, and String Descriptor. idVendor(2byte), idProduct(2byte),
bcdDevice(2byte), iManufacturer(1byte), iProduct(1byte) in Device Descriptor and related String Descriptor can be customized.
Microwire^TM type, 1K bit, 2K bit, or 4K bit EEPROM can be used. Note that word length of iManufacterer and
iProduct is fixed to 52 bytes each for 1K bit EEPROM, 102 bytes for 2K/4K bit EEPROM.
The AK5371A automatically reads Device Descriptor from the EEPROM and stores internal memory after USB reset.
When the AK5371A receives “GET String Descriptor" request, the AK5371A starts reading from EEPROM. The AK5371A
continues to send NAK packet while it is reading String from EEPROM.
Memory mapping of EEPROM is the following.
Device Descriptor (18 bytes)
String Descriptor Lang ID (4 bytes index = 0)
String Descriptor iManufacturer (52 or 102bytes index =1)
String Descriptor iProduct (52 or 102 bytes index = 2)
Note that EEPROM address is 16bit boundary.
1K bit
(AK93C45A)
00h - 08h
09h - 0Ah
0Bh - 24h
25h - 3Eh
2K/4K bit
(AK93C55A / 65A)
00h - 08h
09h - 0Ah
0Bh - 3Dh
3Eh - 71h
If 2K/4K bit EEPROM is used, EPSEL pin should be tied to VD. if 1K bit EEPROM is connected to the device, EPSEL should be
tied to VSS1.
Device Descriptor and String Descriptor should be stored in EEPROM before the AK5371A is powered up. EPEN pin should be tied
to "H" to activate if Descriptors are read from external EEPROM.
If internal ROM is used, not only EPEN pin but also EPSEL pin should be tied to VSS1. Note that CS pin, SK pin, and EPAO
pin are Hi-Z state when EPEN is “L”. EPDI pin is internally pulled down.
MS0546-E-00
MS0103-E-00
13
2007/02